The present invention relates to a semiconductor device, and for example, is used for a resolver to digital converter for converting a signal output from the resolver into a digital signal.
The resolver is known as a rotational angle sensor used in harsh environments, such as for industrial machinery or vehicle power system motors. The resolver outputs an analog sine wave signal indicating the sine of an electrical angle as well as an analog cosine wave signal indicating the cosine of the electrical angle. The resolver to digital converter (hereinafter referred to as R/D converter) converts the sine wave signal and the cosine wave signal into digital values. Then, the resolver calculates the electrical angle based on the sine wave signal and the cosine wave signal that have been digitally converted (see, for example, Japanese Unexamined Patent Application Publication No. 2004-309285 (Patent Document 1)).